Low Poly Model Creation Workflow
As far as I understood, low poly modelling means that you model your meshes using a very low number of polygons (not that you optimize your high poly model).
In this video you can see the workflow, it's very simple and fun:
https://www.youtube.com/watch?v=YALV3HqfdLY
Basically this is the process:

start with a basic shape, go to edit mode and edit it
you can extrude, inset, bevel, loop cut, knife..
proportional editing is also useful sometimes
looptools' relax could be also a nice tool to learn
color (with a simple palette)
done!